Pre trip planning mapping software

I use http://caltopo.com/map.html and also alltrails.com sometimes and import to calptopo and then will print it and use the gaia.com app as well …

Just ran into Caltopo and started playing with it. Looks like those will be better than basecamp for printing. Is there a way to export your created markers and lines from Caltopo into the Gaia mobile app?

> … been using Garmin's Basecamp and I'm finding that some of the distances its giving me are a few miles off known distances.

Map distances are always off because you're measuring a flat surface. The actual trail is three dimensional with ups and downs and small curves not on the map. I always add 20% to distances measured. More if I used paper and string.

This is my map software of choice. The link shows my last trip.

http://www.mappingsupport.com/p/gmap4.php?&t=t7&q=http://www.weddingscr.com/gpx/de_soto/tuxachanie/2015-02february.gpx

Yeah, the issue I'm having is most the distances are close to what I know they are but certain areas are always off. For example, the distance from Guitar Lake to Whitney to the Portal. Both Caltopo and Basecamp appear to be close to 4 miles off, whereas the rest of the trip I have mapped seems pretty close to what I know it to be. Maybe the distances are less accurate with more elevation gain/loss due to the ups and downs you described.

Not mapping, but definitely useful for pre-trip planning is the NOHRSC Interactive Snow Map. Lots of things going on here, but I mostly use it for the snow depth cover (recorded and modeled) overlay to plan early season trips to the high country (Sierra Nevada, CA). See here for example: http://tinyurl.com/lqumfaq

"Is there a way to export your created markers and lines from Caltopo into the Gaia mobile app?"

You bet. There's an 'export' button at the top of the screen that has a 'download as gpx' option. Probably a few ways to do it once you've downloaded the gpx but I always save to a folder in Dropbox on my computer (I imagine any cloud drive installed on your computer and mobile device would work). Next I open the file through the dropbox app on my phone and choose the 'open with gaia gps' option to import.

I use the Delorme Topo North America 9.0 for trip planning. The maps aren't the best quality but I have the whole country on my pc and they are fairly accurate. When figuring out a route the distance takes into account elevation and seems pretty close. I can also draw in a trail if I find one they missed or want to include off trail travel, and it will generate a profile. You can pull up a 3d map but I find that distracting, I've looked at topo's enough over the years that I can visualize the terrain fairly well in 2d. There is also an "export to handheld" tab but I have never played with it as I don't hike with electronics. I don't usually print from the Delorme but just use it for the planning, as I said the map quality isn't that great. When it is time to go I like to get the Trails Illustrated maps for where I am headed and then butcher them down to just the bits I need to save weight. There are probably better programs out there but this is good for planning and dreaming.

This thread has what you need

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=92933

Just click on the dots in the order you want to visit them, click calculate and bingo you have your mileage.
Tracks can then be exported to Caltopo.

Dave

Here are two trips I'm working with right now in caltopo:

http://caltopo.com/map?id=434F (Rae Lakes Loop – Caltopo drawn)
http://caltopo.com/map?id=5P49 (Rae Lakes Loop – via Sierra Mapper)

http://caltopo.com/map?id=7032 (Onion Valley to Whitney)

If I remember correctly, the Rae Lakes Loop is around 42 miles (or is it 46…I can't remember), but I'm getting closer to 37 miles with my hand drawn tracks in Caltopo and 38 miles when mapped in Sierra Mapper. For the Onion Valley trip, I know Day 4 from the Guitar Lake tarns to Whitney to the Portal is longer than the 12 miles its showing. I'm not looking for perfection but these seem like large mileage discrepancies (about 4 miles for each trip) when trying to plan a trip. Am I asking too much of the software?

I'm with Richard on this but maybe not 20%, I usually add 10% onto the distances given. I will sometimes check a trail section with a known/measured distance to see what the deviation is.

I have the old Nat. Geo TOPO for areas I hike in a lot and still find it the easiest to draw routes on but use Gmap4 for a lot of areas I don't have it for to both create routes but to also be able to switch back and forth from topo map to satellite view. Caltopo is definitely the easiest to print from so I will use it for the actual maps I carry.

You know, I've often wondered if there is a standard method of measuring maps that I'm not using. Before computers I'd use a piece of string to trace the route, measure it and work out the distance knowing I had to account for elevation gain. Now I do much the same in Gmap4 but it's more accurate since I can really zoom in on the terrain and plot finer points, the effort is worth while as I can save my work to review later.

It seems that what I've been missing, or at least a way to get closer to a real number, is to add a figure based on elevation gain.

… Time to hit the books! I'm sure there is something I'm missing.

… and five two minutes of searching turned this up:

http://www.justtrails.com/nav-skills/measuring-distance-on-a-topographic-map/

– Flat, scrub desert, or temperate terrain……………add 10%
– Rolling, temperate wooded terrain…………add 20%
– Any loose surface material or snow (to factor in foot slippage)………add 20%
– Jungle or hilly temperate terrain………add 30%
– Sandy desert…………………add 30%
– Mountainous terrain………………………add 40%

Jeff,

Well, *disclaimer*, I created Sierra Mapper. I'd tell you buyer beware, but of course, I know what you paid for it ;).

Early in the process of making Sierra Mapper, I discovered that when the USGS made their quads, they didn't do a particularly good job of placing the the trail where it actually is. It lacks the resolution of the actual trail, and sometimes, goes the wrong way altogether.

Putting trails into Sierra Mapper has become an art. I typically use a combination of satellite imagery, USGS quads, Open Cycle maps, and .gpx files from the community. This works well for the High Sierra, but sometimes–switchbackey stuff under tree cover, e.g.–is rendered in no better accuracy than the USGS quads. Yes, it's quite tedious.

I have previously done some benchmarking:

Sierra Mapper calculates the distance of the High Sierra Trail to be 72.6 miles (the "3D", terrain distance); 72.09 miles (the "2D", linear distance). NPS lists it as 72.2 miles.

Sierra Mapper calculates the distance of the JMT to be 214.5 miles (terrain), 213.3 miles (linear). The accepted values range from 210.4 – 212 miles.

So what's going on with the Rae Lakes Loop? I'm not sure. Certainly, the lower terrain doesn't lend itself well to accurate trail routing. So there may be some low-balling between Road's End and Wood's Creek Crossing, and along Bubb's Creek from Junction Meadow and Road's End. Sierra Mapper calculates 39.4 miles (terrain) and 39.2 miles (linear). What's the true distance? I'm not sure, but I doubt it's 46 miles. My guess is less than 42. I've been wanting to do it in a day, and maybe I will next year. But after I do that, I'll probably swear it's 46 ;).

Regarding Whitney, I've got a Tom Harrison map in front of me. He says that from Crabtree Ranger Station, it's 16.0 miles to the Whitney Summit and down to the portal. Elizabeth Wenk says 17.8 miles. Sierra Mapper says 18.3 miles (terrain), 18.1 miles (linear). My trusty DeLorme software says about 12.4 miles. And I paid for that, y'know?

I realize you are starting from the tarns above Guitar Lake, but those give you an idea of the range of answers you can find from reasonably reputable sources.

In any case, I wouldn't suggest correcting any of the Sierra Mapper distances by 40%. My guess is that the higher elevation stuff is very close (within a few percent). The lower elevation stuff might be further off, but I'd be surprised if it's >10% (unless the USGS did a TERRIBLE job mapping the trail on their quads). I suspect you'll get a closer answer with Sierra Mapper than any other software out there–free or otherwise.

Lastly, if you're not using the Alpha version of Sierra Mapper, you should be. I haven't posted about it here, but it has neat features like off-trail travel and real-time routing. It's linked to from the blog (http://sierramapper.blogspot.com/). It's an Alpha, slightly buggy. Buyer beware.

Adam

Hey Adam,

I appreciate all the info! It does seem like mapping and calculating distances is more of an art. And looks like Rae Lakes Loop is 42 miles which puts your mapping not that far off – I made a chart showing the different measured distances – https://docs.google.com/spreadsheets/d/1L1ymJMR_eN9_WgN-UlDHgBIW9iac7-6FnlO-vLXKHQw/edit?usp=sharing.